Most days of late you would be chasing the cart downhill and losing money. So you buy (transaction fees) - then you have to pay the claim transaction fees (expensive unless you set low gas like 1 gwei) and then move to Bitfinex and trade for Ethereum (transaction fees) and then back out to Metamask (withdrawal fees) and find that you have less Ether than you started with. There were a few periods in July/August where there was a fair amount of market manipulated arbitrage heisted by a coordinated attempt to spam the Ethereum network to prevent contributions in the last 10 mins (happened at least 3 times that I know of). Nowadays, however, there is practically no room for arbitrage through the token distribution as the price is too low and it only takes one whale to push the price over the market. If the price goes up then there may be an opportunity and I expect we may see the Ethereum spam attack back if it looks as if too many whales are waiting for the last minute.
RE: EOS arbitrage